Confused about saves notifications

I saw someone post a screenshot of their activity feed and it had an assortment of “John doe liked your video” and “John doe saved your video” and it’s got me wondering - what does it mean when it says that someone saved their video? Is that them putting it into their bookmarked videos? Or is this them actually downloading the video onto their phone and the person is getting notified that the person did this? I downloaded a video me and an ex made and I didn’t know that notifications got sent….